Method of clamping



March 1967 e. A. ODDSEN METHOD OF CLAMPING Filed July 29, 1965 N i E R mm OD NE T E N qm ET M T W IA U m G 5 MN W0 mm W United States Patent G 3,310,861 METHOD (IF CLAMPING Gustav A. Oddsen, Locust Valley, N.Y., assignor to C- lurnbian Bronze Corporation, Freeport, N.Y., a corporation of New York Filed July 29, 1965, Ser. No. 475,695 4 Claims. (Cl. 29150) This invention relates to a method of securing two different members together to form an article of furniture; more particularly, it relates to such a method in which the furniture is metal of such gage that it can be bent to hold the members firmly together in clamped position.

Wrought iron furniture is conventionally made from a plurality of separate members, the iron being commercially pure and easily forged or welded into various shapes. After welding, the independently forged members constitute a unitary article of furniture, such as a chair, table, stand or the like. With particular respect to wrought iron furniture that includes a work-supporting member, such furniture being exemplified by a chair or table, the member itself, is independently made and then joined to the remainder of the article of furniture. The article of furniture, in addition to the work-supporting member, ordinarily includes legs and a box-like frame into which the work-supporting member is placed. In the case of a chair the work-supporting member will take the form of a seat on which an occupant can rest; in a table, it will be the table top.

A seat member is often made from a thin sheet of metal perforated in an appropriate design, the sheet being bent about the box-like frame and into contact therewith. With the perimeter of the seat member touching the frame, preferably at a surface of the latter not viewable except on close examination, the seat member is welded to the frame at specific locations along the areas of contact of the member and frame. While welding has proved to be an effective method of securing the seat of a chair or top of a table to the frame of the chair or table in a manner such that the chair or table can support relatively heavy loads, it has also proved to be an expensive method of uniting the work-supporting surface and the remainder of the article of furniture. The cost of welding the two parts of wrought iron furniture together has been found to constitute a significant part of the cost of the article, since a large number of separate welds are requisite to assure permanent unity of the two parts.

It is, therefore, an important object of the present invention to provide a method for joining a flexible, worksupporting member to a frame in a manner far more economic than those previously attained and by an operation that is purely mechanical and does not require the services of a skilled artisan to accomplish.

According to the present invention, a seat member or other work-supporting surface is formed with a generally planar surface and a lower surface opposed thereto. A flange depends from the circumference of the seat mem-' her and forms an acute interior angle with the lower surface of the seat member. The frame to which the seat member is to be attached has a vertically depending Wall, a base wall joined to the lowermost end of that wall and extending to one side thereof, and a clamping wall joined to the end of the base wall and terminating in a free end extending toward the depending wall but spaced therefrom. This clamping wall forms an acute interior angle with the base wall.

Having provided a seat member and a frame of the above structure, the seat member is placed on the frame so that the lower surface of the seat member rests on the free end of the clamping wall and the seat member flange extends into the space bounded by the depending wall,

the base wall and the clamping wall of the frame. Pressure is now applied to the seat member in a direction substantially perpendicular to its work-supporting surface.

In this manner the flange is gripped between the clamping wall and the base wall of the frame. Such pressure can be continued until both of the acute interior angles have been closed and the flange and clamping Wall are substantially parallel.

In its most preferred form the present method of securing a seat member to a frame will be found to be one in which the seat member is a four-sided sheet of flexible metal. The four sides will usually be rectilinear. The frame, too, will have four sides, each of which has a vertically depending wall, a base wall and a clamping wall. While the seat member has the same number of sides as the frame, the lengths of each of the sides is somewhat less than the lengths of the corresponding sides of the frame so that the seat member can fit within the frame prior to its joinder to the frame. Each of the sides of the seat member has its own flange depending from the circumference of the seat member.

In order to secure such a seat member to a frame, it has been found most advantageous to apply pressure on all sides of the seat member simultaneously. The application of pressure not only forces the clamping walls and base walls of the frame together to grip the flanges between these walls, but also exerts pressure on the seat member, itself, since the free end of the clamping wall will, upon bending, enter the acute interior angle between the flange and lower surface of the seat member. In this manner the clamping wall free end pushes on the seat member in the direction of the vertically depending wall to which the clamping Wall is connected by the base wall. In simultaneously applying pressure on all four sides of the seat member, this outward pressure is uniformly distributed and the seat member is centrally located with respect to the sides of the frame. In addition, the seat member is uniformly tensioned and thus brought to and maintained in a non-sagging position which is not easily achieved when the seat member is Welded to the frame.

These and other objects, features, and advantages of the present invention will be rendered more readily apparent from an examination of a preferred embodiment of the invention as illustrated in the accompanying drawing, which forms a part hereof, and in which:

FIG. 1 is an exploded, perspective view of an embodiment of a frame and seat member according to my invention, and

FIGS. 2A, 2B, 2C and 2D represent the sectional views of the seat member and frame in cooperating positions, the figures sequentially showing movement of parts of the frame and seat member upon progressive application of force perpendicular to the seat member.

Referring now to the drawing, and in particular to FIG. 1 thereof, it will be seen that the seat member and frame are to be located with respect to each other in a position in which the seat member, indicated generally by a reference numeral 10, is to be positioned within the outline of the frame, indicated generally by reference numeral 11. Portions of both the seat member 10 and frame 11 have been cut away to illustrate the structure of these members in greater detail.

As will be seen both from FIG. 1 and the cross-sectional view of FIG. 2A, the preferred frame 11 is a one piece, box-like structure having a large aperture at its center. In its illustrated form, frame 11 has four sides of equal length. Each side of frame 11 is comprised of a vertical wall 12, which is continuous throughout the four sides of the frame. At its lowermost end the vertical wall 12 is bent inwardly at a -degree angle to form a horizontal base wall 13, which, in turn, is bent upwardly at its end to form a clamping wall 14. While the base wall 13 is bent to form a right angle with vertically depending wall 12, clamping wall 14 is bent more than 90 degrees to form an acute interior angle a with the base wall 13. It is necessary that the angle on be acute, since otherwise the application of force to the seat member 11 will result in deformation of the walls or other parts of the seat member or frame and no unitary, crimped joint between the frame and seat member will result.

As is also apparent from FIGS. 1 and 2A, the seat member 10 is in the form of a substantially flat, thin sheet of metal, the gage of the metal used to form the sheet being somewhat less than that used to form the various walls of the frame 11. Seat member 10 is formed with a substantially flat, upper, work-supporting surface 15 and an opposed, fiat lower surface 16. It will be noted that the seat member is formed with a series of perforations 17 both in order to lighten the weight of the member and to make it more attractive.

At its edges the seat member 10 has a flange 18 which is integral with the seat member. The flange 18 is bent back in the direction of the lower surface 16 of the seat member in such a manner that it forms an acute interior angle ,8 with the lower surface 16 of seat member 10. In the illus trated embodiment, the seat member 10 is four-sided and each of its sides is rectilinear. In such a construction the flange 18 will not be continuous for its entire length along all four sides of the seat member; instead, portions of the flange are cut away at the four corners of the seat member so that the individual flanges 18 can be bent in wardly in the direction of the lower surface 16 without contacting each other at the corners and distorting each other.

Having provided a seat member 10 and frame 11 as illustrated in FIG. 1 of the drawing, the seat member is positioned within the outline of the frame in such a manner that the lower surface 16 of the seat member rests on the free end 19 of the clamping wall 14 of the frame. Since the clamping wall free end 19 extends in the direction of the vertically depending frame wall 12 but does not reach it, room is provided for the flange 18 of the seat member to extend into the space between the clamping wall 14 and depending wall 12 of the frame.

In the illustrated embodiment the seat member flange 18 is not of suflicient length to enable it to contact the base wall 13 of the frame when the seat members rests on the frame as seen in FIG. 2A. The seat member 10 is set in its entirety within the outline of the frame 11. In such position all four sides of the seat member are within the depending wall 12 of the frame 10 and all four flanges 18 of seat member 10 extend within the space bounded by the walls 12, 13 and 14 of the frame. Because the angles are acute, free space between the edges of the seat member and the vertical wall 12 of the frame 11 will be necessary in order to permit the insertion of the seat member within the outlines of the frame. Thus, prior to the application of pressure on the seat member, there may be some play in the seat member to permit minor shifting of its position, which is limited by the walls 12 of the frame. In general, it is most desired that the seat member be located centrally wtih respect to the frame and that spaces between the edges of the seat member and the wall 12 be equally distributed on all sides of the seat member. Having been located in this position, the seat member is ready to be clamped to the frame.

An early stage in the application of pressure vertically against the upper surface 15 of the seat member is illustrated in FIG. 2B. In this figure it will be apparent that the force has initially served to rotate the free end 19 of clamping wall 14 of frame 10 in the direction of the base wall 13 of that frame. In all such application of force, it is presupposed that the frame 11 rests on a supporting surface which is, for the purposes of resisting the force applied to the seat member, substantially immovable. Such bending torque applied to the free end 19 of the clamping wall 14 continues without change until the free end 211 of the flange 13 of the seat member has come into contact with the base wall 13. It is this position of crimping that the seat member and frame are illustrated in FIG. 2B. In that figure, the flanges 18 have just made contact with the base walls 13, because pressure is being applied simultaneously to all four sides of the seat memher 111.

In FIG. 2C, an intermediate stage in the application of pressure perpendicularly downward against all four sides of seat member 10 is illustrated. Upon this further application of pressure, the free end 2d of flange 18 has been forced in the direction of the lower surface 16 of the seat member. As the flange 18 moves toward the lower surface 16, the angle 5 becomes smaller, as does the angle a of the frame 10. With the depression of the seat member as illustrated in FIG. 2C, the clamping wall 14 of the frame has been further depressed toward the base wall 13. Both angles a and B have been substantially diminished and the free end 19 of the clamping wall 16 has begun to enter the angle 3.

The final stage in the clamping together of the seat member 10 and frame 11 is illustrated in FIG. 2D. In this figure the angles on and 5 have substantially disappeared and the base wall 13, clamping wall 14, flange 18, and seat member 10 are all substantially parallel. While free end 20 of flange 18 has not substantially entered the angle a of the frame part, clamping wall 14 is of sufficient length so that free end 19 enters the former angle 3 and occupies it, pushing in an outward direction on the seat member 10. By adjustment of the length of the clamping wall 14, the degree of tension on the seat member 10 can be regulated. In most cases the clamping wall 14 will be made long enough so that some tension is created in the seat member.

The means for applying pressure to the seat member 10 has only been illustrated in a diagrammatic manner in FIGS. 2A to 2D. The particular means used for applying such pressure is not of importance. In the illustrated, preferred embodiment, however, it is important that such pressure he applied equally and simultaneously to all four side areas of the seat member and that the direction of such application be vertically downward in the direction of the base wall 13 of the frame. Thus, the means for applying pressure has only been indicated by broken lines 21 in FIGS. 2B, 2C, and 2D.

The method described with reference to the illustrated embodiment hereinbefore will accomplish the uniting of a seat member having a work-supporting surface and a frame, with the frame member preferably being composed of cold rolled steel. The members are preferably square or rectangular, but can be oval, circular, or otherwise, or even kidney-shaped. As it has been stated hereinbefore, this method of uniting these two members requires no welding and does not necessitate the utilization of a skilled worker; instead, it can be completely accomplished by machine means, for example, by means of a plunger that is automatically actuated when the seat member and frame are aligned in proper position beneath it. Moreover, in addition to the function of permanently uniting the seat member and frame, the present method serves to apply uniform tension to the seat member to enable the upper surface of that member to be substantially planar even when loads are placed on it. The tension under which the seat member is maintained aids it in supporting articles and, in addition, provides it with a resilience that would not be present were the seat member under no tension. Consequently, the present method provides for two improvements over the conventional method of joining members in but a single step.

In will be apparent that certain modifications and alterations in the invention described hereinbefore will be obvious to those skilled in this art. All such obvious changes are deemed to be included within the scope of the present invention, which is to be limited only by the purview of the following, appended claims.

What is claimed is:

1. A method of securing a seat member having a generally planar work-supporting surface to a frame, comprising providing a frame having at least three sides joined to each other to form a rigid unit, each of said sides being formed with a vertically depending wall, a base wall joined to the lowermost end of said depending wall and extending to one side thereof, and a clamping wall joined to the end of said base wall and terminating in a free end extending toward said depending wall but spaced therefrom, said clamping wall forming an acute interior angle with said base wall,

providing a seat member having the same number of sides as said frame, each of said sides being shorter than its corresponding side of said frame and having a generally planar upper work-supporting surface opposed by a lower surface and a flange depending from the circumference of said seat member and forming an acute interior angle with said lower surface of said seat member,

placing said seat member on said frame in a position in which corresponding sides of said seat member and said frame are parallel, said lower surface of said seat member rests on said free end of said clamping wall and each of said flanges extends into the space bounded by a depending wall, a base wall and a clamping wall of the corresponding side of said frame,

and simultaneously applying pressure to all of the sides of said seat member in a direction substantially perpendicular to said work-supporting surface until each of said flanges is gripped between a clamping wall and a base wall of one side of said frame.

2. A method of securing a rectilinear seat member having a generally planar work-supporting surface to a frame, comprising providing a frame bounded by four straight sides each of which is formed with a vertically depending wall, a base Wall joined to the lowermost end of said depending wall extending to one side thereof and forming a right angle therewith, and a clamping wall joined to the end of said base wall and terminating in a free end extending toward said depending wall but spaced therefrom, said clamping wall forming an acute interior angle with said base wall,

providing a seat member having four sides each of which is shorter than its corresponding side of said frame and a generally planar upper work-supporting surface opposed by a lower surface, each of said sides being formed with a flange depending from the circumference of said seat member and forming an.

acute interior angle with said lower surface of said seat member,

placing said seat member on said frame in a position in which corresponding sides of said seat member and said frame are parallel, said lower surface of said seat member rests on said free end of said clamping wall and each of said flanges extends into the space bounded by a depending wall, a base wall and a clamping wall of the corresponding side or said frame,

simultaneously applying pressure to all of the sides of said seat member in a direction substantially perpendicular to said work-supporting surface until each of said flanges is gripped between a clamping wall and a base wall of one side of said frame,

and continuing to apply said pressure until said acute interior angles have been closed and said flanges and said clamping walls are substantially parallel.

3. A method of securing a seat member having a gem erally planar work-supporting surface to a frame, comprising providing a frame having a plurality of sides joined to form a rigid unit, each of said sides being formed with a vertically depending wall, a base wall joined to the lowermost end of said depending wall and extending to one side thereof, and a clamping wall joined to the end of said base wall and terminating in a free end extending toward said depending wall but spaced therefrom, said clamping wall forming an acute interior angle with said base wall,

providing a seat member having the same number of sides as said frame, each of said sides being shorter than its corresponding side of said frame and having a generally planar upper work-supporting surface opposed by a lower surface, and a flange depending from the circumference of said seat member and forming an acute interior angle with said lower surface of said seat member,

placing said seat member on said frame in a position in which corresponding sides of said frame and said seat member are adjacent each other, said lower surface of said seat member rests on said free end of said clamping wall and each of said flanges extends into the space bounded by a depending wall, a base wall and a clamping wall of said frame,

and applying pressure to said seat member in a direction substantially perpendicular to said work-sup.- porting surface until each of said flanges is gripped between a clamping wall and a base Wall of one side of said frame.

4. A method of securing a seat member having a generally planar work-supporting surface to a frame, comprising providing a frame having a plurality of sides joined to form a rigid unit, each of said sides being formed with a vertically depending wall, a base Wall joined to the lowermost end of said depending wall and extending horizontally therefrom, and a clamping wall joined to the end of said base wall and terminating in a free end extending toward said depending wall but spaced therefrom, said clamping wall forming an acute interior angle with said base wall,

providing a seat member having the same number of sides as said frame, each of said sides being shorter than its corresponding side of said frame and having a generally planar upper work-supporting sunface opposed by a lower surface, and a flange depending from the circumference of said seat member and forming an acute interior angle with said lower surface of said seat member,

placing said seat member on said frame in a position in which corresponding sides of said frame and said seat member are adjacent each other, said lower surface of said seat member rests on said free end of said clamping wall and each of said flanges extends into the space bounded by a depending wall, a base wall and a clamping wall of said frame, applying pressure to said seat member in a direction substantially perpendicular to said work-supporting surface until each of said flanges is gripped between a clampifig wall and a base wall of one side of said frame, and continuing to apply said pressure until said acute interior angles have been closed and said flanges and said clamping walls are substantially parallel.

References Cited by the Examiner UNITED STATES PATENTS 1,722,256 7/1929 Wikstr-om 29505 X 1,906,603 5/1933 Hungerford 994S0 1,940,636 12/1933 Stubnitz 2991.1

JOHN F. CAMPBELL, Primary Examiner.

THOMAS H. EAGER, Examiner, 

1. A METHOD OF SECURING A SEAT MEMBER HAVING A GENERALLY PLANAR WORK-SUPPORTING SURFACE TO A FRAME, COMPRISING PROVIDING A FRAME HAVING AT LEAST THREE SIDES JOINED TO EACH OTHER TO FORM A RIGID UNIT, EACH OF SAID SIDES BEING FORMED WITH A VERTICALLY DEPENDING WALL, A BASE WALL JOINED TO THE LOWERMOST END OF SAID DEPENDING WALL AND EXTENDING TO ONE SIDE THEREOF, AND A CLAMPING WALL JOINED TO THE END OF SAID BASE WALL AND TERMINATING IN A FREE END EXTENDING TOWARD SAID DEPENDING WALL BUT SPACED THEREFROM, SAID CLAMPING WALL FORMING AN ACUTE INTERIOR ANGLE WITH SAID BASE WALL, PROVIDING A SEAT MEMBER HAVING THE SAME NUMBER OF SIDES AS SAID FRAME, EACH OF SAID SIDES BEING SHORTER THAN ITS CORRESPONDING SIDE OF SAID FRAME AND HAVING A GENERALLY PLANAR UPPER WORK-SUPPORTING SURFACE OPPOSED BY A LOWER SURFACE AND A FLANGE DEPENDING FROM THE CIRCUMFERENCE OF SAID SEAT MEMBER AND FORMING AN ACUTE INTERIOR ANGLE WITH SAID LOWER SURFACE OF SAID SEAT MEMBER, PLACING SAID SEAT MEMBER ON SAID FRAME IN A POSITION IN WHICH CORRESPONDING SIDES OF SAID SEAT MEMBER AND SAID FRAME ARE PARALLEL, SAID LOWER SURFACE OF SAID SEAT MEMBER RESTS ON SAID FREE END OF SAID CLAMPING WALL AND EACH OF SAID FLANGES EXTENDS INTO THE SPACE BOUNDED BY A DEPENDING WALL, A BASE WALL AND A CLAMPING WALL OF THE CORRESPONDING SIDE OF SAID FRAME, AND SIMULTANEOUSLY APPLYING PRESSURE TO ALL OF THE SIDES OF SAID SEAT MEMBER IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO SAID WORK-SUPPORTING SURFACE UNTIL EACH OF SAID FLANGES IS GRIPPED BETWEEN A CLAMPING WALL AND A BASE WALL OF ONE SIDE OF SAID FRAME. 